XXY

A term for the chromosomal pattern that causes a condition called Klinefelter syndrome, an intersex condition in which a person assigned male at birth has an extra X chromosome.

This can cause a number of common symptoms, including:

• Taller bodies, prone to less muscle
• Broader hips and reduced upper body strength
• Gynecomastia (development of breast tissue on an AMAB body)
• Smaller genitals
• High infertility rate

Frequently, the symptoms can be treated with hormone therapy (testosterone), though this will not reverse every physical change, particularly if done post-puberty (when most are diagnosed).